Lets put an end to this "Mast Bumping" is a Mortal Sin thing.....it is an issue for sure but then so is any number of other issues for other designs.
Take one look at the number of flight hours for the Bell 47, 204, 205, 212,214, including Military models all. using that style Rotor Head system....and I would suggest Mast Bumping is one of the least notable causes of accidents.
Yes...you can do yourself in if you allow the factors that cause Mast Bumping to occur....but there lies the central issue....the PILOT!
Robbies do the Mast Bumping thing because the tolerances are so much smaller than that on a Huey....and the same is true for the Bell 47 compared to the 212 or 214.
That tells me that one has to be far more judicious in choosing the conditions and manner one flies the Robbie than the larger better built aircraft.
Note: The US Army fleet of UH-1's accumulated almost Eight Million Flight Hours during the Vietnam War....and many of those same Huey's are still flying today in the Civilian Market.
Add the other militaries in the USA and around the world, and civilian operators and the total fleet hours are well beyond Ten Million Hours and counting.
That is not Robbie Bashing....that is just the plain ol' truth.
Since I am even thinking about Robbies....I shall go have a couple of double Cheeseburgers with a large order Fries (Chips) and a large Chocolate Milkshake.....to ensure I cannot fit through the door of a Robbie.
https://vtol.org/files/dmfile/50-52H...rdinkSO162.pdf